There are a variety of applications in which a single dose of a medicine, reagent, or other material is packaged in a disposable container under sealed conditions. Often times, these packages include a method for opening the assembly to provide access to the contents of the container without resort to additional tools or equipment.
One form of these containers may be generally described as a container having the nozzle for discharge of the contents, wherein the nozzle supports a stem like element on a frangible diaphragm molded or otherwise formed in the discharge opening. The cap is somehow caused to interact with the stem, usually with the use of a socket, whereby a fit between the stem and socket ruptures the frangible diaphragm and causes removal of the stem.
One example of this device is shown in the U.S. Pat. No. 4,773,584. In this patent, a cap and tube are combined such that a frangible web supports a projection which has knurling thereon. The cap is initially mounted on the nozzle of the tube to protect the projection. The cap has an end for acting as a cover with a reverse end having a central socket, and having axially extending ribs. The ribs and the knurling frictionally engage and interlock with each other. The obvious drawback of this design is that the activation end of the cap is exposed to the outside and can become contaminated. In addition, the cap must be taken off and turned over in order to activate the system. This requires both hands at some time during the removal of the stem or projection.
A design which avoids the sanitation problems of the above identified patent, is shown in U.S. Pat. No. 4,134,511. This patent describes a container with a neck having an elongated solid projection on the tip. The projection is integrally connected to the tip by a reduced wall portion forming a frangible annular link whose rupture creates an outlet. The neck is closely surrounded by a cap which firmly engages this removable tip and cannot be detached until the tip has been broken off. In other words, the tip is firmly mounted in the cap.
As shown in U.S. Pat. No. 4,134,511, the tip has a smooth surface close to the neck but is polygonal over the greater part of its length. A hexagonal shape is preferred. This tip is then press fit into a socket of the same polygonal shape and both the tip and the socket have a slight taper to limit the extent to which the neck can be inserted into the cap.
The problems with this design are several. First, there is no way to prevent the, tip from being pushed into the container when an axial force is inadvertently applied to the cap. Since the tip and cap are always in contact, there is a serious risk of inadvertent activation. Any time there is a one step activation, it is possible for children and others not authorized to have access to the contents to inadvertently or intentionally open the product. Another drawback of this design is that axial activation is possible even though the design is intended to have a rotational movement to cause the fracture or rupture of the frangible area holding the tip on the nozzle. Finally, the tip is mounted to the nozzle at the top of the nozzle. When the container is used for eye drops, removal of the cap may provide a torn edge of the frangible portion which may scrape or scratch the eye. Similarly, when baby vitamins are dispensed from the container, a quick movement by the child could cause a cut or worse.
Accordingly, it is an object of the present invention to provide a safe and efficient method for storing and dispensing materials in a container.
Another object of the present invention is to provide a container of the type described which employs a stem and socket in a manner which avoids the problems of the prior art and which provides additional benefits and safety features.
Specifically, it is an object of this invention to provide a cap and tube assembly which normally exists in a non-activated condition and which requires a multiple step activation process prior to discharge of the contents. Other objects appear hereinafter.